The library includes new collection types for Multimap, Multiset, and Bitmap, a MapMaker builder for concurrent hash maps, and an Ordering collection Google described as "Comparator on steroids." You can read more here.

Jared Levy, one of the primary creators with Google colleague Kevin Bourrillion, toldJavaLobby the main benefit for developers is convenience.

"The library's functionality simplifies your code so it's easier to write, read, and maintain," he told JavaLobby. "The Google Collections Library will improve your productivity as a developer, while reducing the amount of boilerplate low-level code you need to write."

Not everyone sees Google's code as the answer to making the notoriously complex Java easier to work with. Author Elliotte Rusty Harold wrote while Google's code saves additional typing it creates extra dependencies and may mean using additional code you don't need.

Looking ahead, Google said it plans to fold the Google Collections Library into its Guava Project for libraries in the "near future." Also planned: support for Java 6. Version 1.0 works on Java 5. Google blogged it "deprioritized" Java 6, saying it could deliver "99 per cent of the value while sticking to Java 5, so it's senseless to cut off a large chunk of user base." ®